Calling induce() from cppyy reports an error but actually works

[saraedum]

The first time we call induce() on an IET, cppyy reports something like this:

input_line_41:3:40: error: cannot initialize a member subobject of type 'intervalxt::InductionStep::Result' with an lvalue of type 'const int'
  self = new intervalxt::InductionStep{result, connection, additionalIntervalExchangeTransformation};
                                       ^~~~~~
input_line_41:3:60: error: call to implicitly-deleted copy constructor of 'std::optional<IntervalExchangeTransformation>'
  self = new intervalxt::InductionStep{result, connection, additionalIntervalExchangeTransformation};
                                                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/jule/proj/conda/miniconda3/envs/flatsurf/bin/../lib/gcc/x86_64-conda-linux-gnu/9.3.0/../../../../x86_64-conda-linux-gnu/include/c++/9.3.0/optional:658:7: note: copy constructor of 'optional<intervalxt::IntervalExchangeTransformation>' is implicitly deleted because base class
      '_Enable_copy_move<is_copy_constructible_v<intervalxt::IntervalExchangeTransformation>,
      __and_v<is_copy_constructible<intervalxt::IntervalExchangeTransformation>, is_copy_assignable<intervalxt::IntervalExchangeTransformation> >,
      is_move_constructible_v<intervalxt::IntervalExchangeTransformation>, __and_v<is_move_constructible<intervalxt::IntervalExchangeTransformation>,
      is_move_assignable<intervalxt::IntervalExchangeTransformation> >, optional<intervalxt::IntervalExchangeTransformation> >' has a deleted copy constructor
      private _Enable_copy_move<
      ^
/home/jule/proj/conda/miniconda3/envs/flatsurf/bin/../lib/gcc/x86_64-conda-linux-gnu/9.3.0/../../../../x86_64-conda-linux-gnu/include/c++/9.3.0/bits/enable_special_members.h:157:15: note: '_Enable_copy_move' has been explicitly marked deleted here
    constexpr _Enable_copy_move(_Enable_copy_move const&) noexcept  = delete;

This is https://bitbucket.org/wlav/cppyy/issues/305/initialization-of-struct-reports-an-error. We could work around by creating a constructor it seems.